1996 TOYOTA LAND CRUISER sensor

A00068
Knock signal waveform
0.5V/
Division
0.5V/
Division 0V
0V 5 m sec./Division
200
sec./Division
−
DIAGNOSTICS ENGINE
DI−61
1996 LAND CRUISER (RM451U)
4 Does malfunction disappear when a good knock sensor is installed?
YES Replace knock sensor.
NO
Check and replace ECM (See page IN−28 ).
Reference: INSPECTION USING OSCILLOSCOPE
With the engine racing (4,000 rpm) measure between ter-
minals KNK1, KNK2 of ECM and body ground.
HINT:
The correct waveform is as shown.
Spread the time on the horizontal axis, and confirm that
period of the wave is 164 μ sec. (Normal mode vibration
frequency of knock sensor: 6.1 kHz).
HINT:
If normal mode vibration frequency is not 6.1 kHz the sensor is
malfunctioning.
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S06273
E1
1
G−
2
BR
L
L G1
NE2
NE2−
12
E6
3
2
Distributor
Crankshaft Position Sensor G2
ECM
NE
4
1 L
L
G W
R
E6
E6
E6
E6
E6 11
10 4
56
DI−62
−
DIAGNOSTICS ENGINE
1996 LAND CRUISER (RM451U)
DTC P0335 Crankshaft Position Sensor ”A” Circuit Malfunction
CIRCUIT DESCRIPTION
The crankshaft position sensor (NE signal) consists of a signal plate and pick up coil. The NE\
signal plate
has 24 teeth and is built into the distributor. When the camshaft rotates, the protrusion on the signal plate
and the air gap on the pick up coil change, causing fluctuations in the magnetic field and generating an elec-
tromotive force in the pick up coil. The NE signal sensor generates 24 signals fo\
r every engine revolution.
The ECM detects the standard crankshaft angle based on the G1, G2 signals, \
detects the actual crankshaft
angle and the engine speed by the NE signals, and detects misfire by NE2 sign\
als.
DTC No.DTC Detecting ConditionTrouble Area
P0335
No crankshaft position sensor signal (NE signal) to ECM dur-
ing cranking.
(2 trip detection logic) Open or short in crankshaft position sensor circuit for NE
signal.
 Crankshaft position sensor for NE signal
 Starter
 ECM
No crankshaft position sensor signal (NE signal) to ECM with
engine speed 550 rpm or more (2 trip detection logic)
WIRING DIAGRAM
DI5PH−02
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P24663
1
23
4
(−) (+)
P23505
G, NE signal waveforms
20 m sec/Division (Idling) 5V/DIV
G1
G2
NE
NE2
−
DIAGNOSTICS ENGINE
DI−63
1996 LAND CRUISER (RM451U)
INSPECTION PROCEDURE
1 Check resistance of crankshaft position sensor for NE signal.
PREPARATION:
Remove the distributor cap and disconnect distributor connec-
tor.
CHECK:
Measure resistance between terminals 1 and 4 of distributor
connector.
OK:
Resistance
Cold185 − 275 Ω
Hot240 − 325 Ω
”Cold” is from − 10°C (14F° ) to 50°C (122°F) of engine coolant
temperature sensor and ”Hot” is from 50 °C (122° F) to 100° C
(212 °F).
Reference: INSPECTION USING OSCILLOSCOPE
During cranking or idling, check between terminals G1, G2, NE,
NE2 and G− of ECM.
HINT:
The correct waveforms are as shown.
NG Replace distributor housing assembly.
OK
2 Check for open and short in harness and connector between ECM and crank-\
shaft position sensor for NE signal (See page IN−28).
NG Repair or replace harness or connector.
OK
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P24663
2(−)
3
4 1
(+)
−
DIAGNOSTICS ENGINE
DI−65
1996 LAND CRUISER (RM451U)
DTC P0340 Camshaft Position Sensor Circuit
Malfunction
CIRCUIT DESCRIPTION
The camshaft position sensors (G1 and G2 signals) consist of a signal pla\
te and a pick up coil. The G1, G2,
signal plates each have one tooth on the outer circumference and are built int\
o the distributor. When the
camshaft rotates, the protrusion on the signal plate and the air gap on the pick \
up coil change, causing fluc-
tuations in the magnetic field and generating an electromotive force in the pick \
up coil. The ECM detects the
standard crankshaft angle based on the G1, G2 signals, detects the actual cranks\
haft angle and engine
speed by the NE signals, and detects misfire by NE2 signals.
DTC No.DTC Detecting ConditionTrouble Area
P0340No camshaft position sensor signal (G signal) to ECM with
engine speed 550 rpm or more. Open or short in camshaft position sensor circuit
 Camshaft position sensor
 ECM
WIRING DIAGRAM
Refer to DTC P0335 (Crankshaft Position Sensor ”A” Circuit Malfunction) o\
n page DI−62 for the WIRING
DIAGRAM.
INSPECTION PROCEDURE
1 Check resistance of camshaft position sensor.
PREPARATION:
Disconnect camshaft position sensor connector.
CHECK:
Measure resistance between terminals 2, 3 and 4 of distributor
connector.
OK:
Resistance
Cold185 − 275 Ω
Hot240 − 325 Ω
”Cold” is from − 10°C (14°F) to 50°C (122°F) of engine coolant
temperature and "Hot" is from 50°C (122°F) to 100°C (212°\
F).
Reference: INSPECTION USING OSCILLOSCOPE
Refer to page DI−62 for Reference INSPECTION USING OS-
CILLOSCOPE.
NG Replace distributor housing assembly.
OK
DI5PI−02
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DI−66
−
DIAGNOSTICS ENGINE
1996 LAND CRUISER (RM451U)
2 Check for open and short in harness and connector between ECM and camshaft
position sensor (See page IN−28).
NG Repair or replace harness or connector.
OK
3 Check air gap (See page IG−1 ).
NG Replace distributor housing assembly.
OK
Check and replace ECM (See page IN−28 ).
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A00167P22894
P24664
−
DIAGNOSTICS ENGINE
DI−67
1996 LAND CRUISER (RM451U)
DTC P0385 Crankshaft Position Sensor ”B” Circuit
Malfunction
CIRCUIT DESCRIPTION
The crankshaft position sensor (NE2 signal) consists of a signal plate and a pick up coil. The NE2 signal plate
has 34 teeth and is mounted on the crankshaft. When the crankshaft rotates, the protrusion on the signal
plate and the air gap on the pick up coil change, causing fluctuations i\
n the magnetic field and generating
an electromotive force in the pick up coil. The NE2 signal sensor generate\
s 34 signals for every engine revo-
lution. The ECM detects the standard crankshaft angle based on G1, G2 signals d\
etects the actual crank-
shaft angle and the engine speed by NE signals, and detects misfire by NE2 si\
gnals.
DTC No.DTC Detecting ConditionTrouble Area
P0385
No crankshaft position sensor signal (NE 2 signal) to ECM
during cranking. (2 trip detection logic) Open or short in crankshaft position sensor for NE2 signals.
 Crankshaft position sensor for NE2 signal.
 ECM
No crankshaft position sensor signal (NE 2 signal) to ECM with
engine speed 550 rpm or more. (2trip detection logic)
WIRING DIAGRAM
Refer to DTC 0335 (Crankshaft Position Sensor ”A” Circuit Malfunction)\
on page DI−62 for WIRING DIA-
GRAM.
INSPECTION PROCEDURE
1 Check resistance of crankshaft position sensor for NE2 signal.
PREPARATION:
Disconnect crankshaft position sensor connector.
CHECK:
Measure resistance between terminals 1 and 2 of crankshaft
position sensor connector.
OK:
Resistance
Cold1630 − 2740 Ω
Hot2065 − 3225 Ω
”Cold” is from − 10°C (14°F) to 50°C (122°F) of engine coolant
temperature and "Hot" is from 50°C (122°F) to 100°C (212°F).
Reference: INSPECTION USING OSCILLOSCOPE
Refer to page DI−62 for Reference INSPECTION USING OS-
CILLOSCOPE.
NG Replace crankshaft position sensor.
OK
DI5PJ−02
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DI−68
−
DIAGNOSTICS ENGINE
1996 LAND CRUISER (RM451U)
2 Check for open and short in harness and connector between ECM and crank-
shaft position sensor for NE2 signal (See page IN−28).
NG Repair or replace harness or connector.
OK
3 Inspect sensor installation and teeth of signal plate.
NG Tighten the sensor. Replace signal plate.
OK
Check and replace ECM (See page IN−28 ).
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P22417
Exhaust
Gas
Intake Air
Chamber EGR
Valve
VSV
EGR
Vacuum
Modulator
ECM
Throttle
valve
P22426
BR
From Battery R/B No.2
R−Y
2
222
2
2
Y−R
EFI Main
Y−R
1
2
43
REA2
EZ1
EB12 7
VSV for EGR 21
YYL
−W
EZ14
EGR Gas T emp.
Sensor
21
G−Y
BR−BE7 E4
E4
E5 3
22
19
9
THG
E1
EGR
E2 5V
MRLY
ECM
R
EB
EFI
1
Relay
B+
E01
−
DIAGNOSTICS ENGINE
DI−69
1996 LAND CRUISER (RM451U)
DTC P0401 Exhaust Gas Recirculation Flow Insufficient
Detected
CIRCUIT DESCRIPTION
The EGR system recirculates exhaust gas, which is controlled to the proper \
quantity to suit the driving condi-
tions, into the intake air mixture to slow down combustion, reduce the combust\
ion temp. and reduce NOx
emissions. The amount of EGR is regulated by the EGR vacuum modulator ac\
cording to the engine load.
If even one of the following conditions is fulfilled, the VSV is
turned ON by a signal from the ECM.
This results in atmospheric air acting on the EGR valve, closing
the EGR valve and shutting off the exhaust gas (EGR cut− off).
Under the following conditions, EGR is cut to maintain driveabil-
ity.
Before the engine is warmed up.
During deceleration (throttle valve closed).
Light engine load (amount of intake air very small).
Engine racing.
DTC No.DTC Detecting ConditionTrouble Area
P0401
After the engine is warmed up and run at 80 km/h (50 mph)
for 3 to 5 minutes, the EGR gas temperature sensor value
does not exceed 38° C (100.4°F) above the ambient air tem-
perature. (2 trip detection logic) EGR valve stuck closed
 Short in VSV circuit for EGR
 Open in EGR gas temp. sensor circuit
 EGR hose disconnected
 ECM
WIRING DIAGRAM
DI5PK−02
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